TY - JOUR
T1 - Daytime light exposure dynamically enhances brain responses
AU - Vandewalle, Gilles
AU - Balteau, Evelyne
AU - Phillips, Christophe
AU - Degueldre, Christian
AU - Moreau, Vincent
AU - Sterpenich, Virginie
AU - Albouy, Geneviève
AU - Darsaud, Annabelle
AU - Desseilles, Martin
AU - Dang-Vu, Thien Thanh
AU - Peigneux, Philippe
AU - Luxen, André
AU - Dijk, Derk-Jan
AU - Maquet, Pierre
PY - 2006/8/22
Y1 - 2006/8/22
N2 - In humans, light enhances both alertness and performance during nighttime and daytime [1-4] and influences regional brain function [5]. These effects do not correspond to classical visual responses but involve a non-image forming (NIF) system, which elicits greater endocrine, physiological, neurophysiological, and behavioral responses to shorter light wavelengths than to wavelengths geared toward the visual system [6-11]. During daytime, the neural changes induced by light exposure, and their time courses, are largely unknown. With functional magnetic resonance imaging (fMRI), we characterized the neural correlates of the alerting effect of daytime light by assessing the responses to an auditory oddball task [12-15], before and after a short exposure to a bright white light. Light-induced improvement in subjective alertness was linearly related to responses in the posterior thalamus. In addition, light enhanced responses in a set of cortical areas supporting attentional oddball effects, and it prevented decreases of activity otherwise observed during continuous darkness. Responses to light were remarkably dynamic. They declined within minutes after the end of the light stimulus, following various region-specific time courses. These findings suggest that light can modulate activity of subcortical structures involved in alertness, thereby dynamically promoting cortical activity in networks involved in ongoing nonvisual cognitive processes.
AB - In humans, light enhances both alertness and performance during nighttime and daytime [1-4] and influences regional brain function [5]. These effects do not correspond to classical visual responses but involve a non-image forming (NIF) system, which elicits greater endocrine, physiological, neurophysiological, and behavioral responses to shorter light wavelengths than to wavelengths geared toward the visual system [6-11]. During daytime, the neural changes induced by light exposure, and their time courses, are largely unknown. With functional magnetic resonance imaging (fMRI), we characterized the neural correlates of the alerting effect of daytime light by assessing the responses to an auditory oddball task [12-15], before and after a short exposure to a bright white light. Light-induced improvement in subjective alertness was linearly related to responses in the posterior thalamus. In addition, light enhanced responses in a set of cortical areas supporting attentional oddball effects, and it prevented decreases of activity otherwise observed during continuous darkness. Responses to light were remarkably dynamic. They declined within minutes after the end of the light stimulus, following various region-specific time courses. These findings suggest that light can modulate activity of subcortical structures involved in alertness, thereby dynamically promoting cortical activity in networks involved in ongoing nonvisual cognitive processes.
KW - Acoustic Stimulation
KW - Adult
KW - Analysis of Variance
KW - Attention
KW - Brain
KW - Cognition
KW - Humans
KW - Magnetic Resonance Imaging
KW - Photic Stimulation
KW - Sunlight
KW - Time Factors
U2 - 10.1016/j.cub.2006.06.031
DO - 10.1016/j.cub.2006.06.031
M3 - Article
C2 - 16920622
SN - 0960-9822
VL - 16
SP - 1616
EP - 1621
JO - Current biology : CB
JF - Current biology : CB
IS - 16
ER -